Psoriasis may increase the risk for diabetes
MedWire News: Results from a systematic review and meta-analysis indicate that psoriasis is a risk factor for diabetes.
Several previous studies have shown an association between psoriasis and diabetes, but others have not.
"The reasons for this difference are not quite clear but probably due to poor design, inadequate size, the severity of psoriasis, and consequent lack of power," write Juan Cheng (Beijing 302 Hospital, China) and colleagues.
To clarify the issue, Cheng and team analyzed data from 22 published studies performed in the USA (n=4), Europe (n=12), and Asia (n=6), including a total of 3,307,516 participants.
To be included, studies had to have a comparison control group, present original data, and have incidence of diabetes associated with psoriasis as an outcome.
The team calculated that patients with psoriasis had a significant 42% increased risk for developing diabetes overall compared with those without the condition. In total, psoriasis significantly increased the risk for diabetes in 15 of the 22 studies.
The Newcastle-Ottawa Scale was used to assess study quality, but removal of four "lower quality" studies did not significantly influence the overall result.
Geographic location seemed to affect the association to some degree, with a stronger link observed in the Asian compared with the European and American studies.
Cheng et al note that due to the observational nature of the original studies, potential confounding cannot be excluded as a possible cause of the association. Confounding factors could include smoking, obesity, and presence of the metabolic syndrome, all of which have previously been shown to increase the risk for developing diabetes.
"More research, both epidemiological and mechanistic, is needed to further clarify the association between psoriasis and risk of diabetes," write the authors in the Archives of Dermatological Research.
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By Helen Albert